The electricity price is linked to the gas price due to the fraction of electricity generated by burning gas. As long as the electricity price remains inflated by statutory charges and the gas is subsidised I cannot see a heat pump being more economical than a gas boiler other than over short price catch-up periods.
Now if the government decided to end all fossil fuel subsidies/tax advantages and use the money on electricity infrastructure and renewable generation, that would be another matter.
Some vague statement of intent has been made but in the meantime any efforts to eliminate gas boilers will fail. A relatively small number of people will change their own homes on principle and because they can afford to but the vast majority will wait to the last minute.
Also, world wide, heat pumps are a major product and the government’s suggestion that increasing sales from a few thousand a year to a few tens of thousands a year will have a major impact on prices is balderdash (showing my age with that word!) On a global scale the change will be peanuts.